doi: 10.1130/G33006.1 2012;40;675-678 Geology M.T. Gonzalez-Muñoz, F. Martinez-Ruiz, F. Morcillo, J.D. Martin-Ramos and A. Paytan barite formation Precipitation of barite by marine bacteria: A possible mechanism for marine Email alerting services articles cite this article to receive free e-mail alerts when new www.gsapubs.org/cgi/alerts click Subscribe to subscribe to Geology www.gsapubs.org/s...

Bacterial precipitation of barite (BaSO(4)) under laboratory conditions is reported for the first time. The bacterium Myxococcus xanthus was cultivated in a solid medium with a diluted solution of barium chloride. Crystallization occurred as a result of the presence of live bacteria and the bacterial metabolic activity. A phosphorous-rich amorphous phase preceded the more crystalline barite for...

Ra, Ra and Ba distributions as well as Ra/Ra and Ra/Ba ratios were measured in seawater, suspended and sinking particles at the DYFAMED station in the Western Mediterranean Sea at different seasons of year 2003 in order to track the build-up and fate of barite through time. The study of the Raex/ Raex ratios (Raex = Ra activities corrected for the lithogenic Ra) of suspended particles suggests ...

Pseudomorphs of barite (BaSO4) and Cd-rich ZnS after whewellite (CaC2O4·H2O) occur within remnants of Scots pine bark tissues in the peat layer of a poor fen located near a zinc smelter in south Poland. A two-step formation of the pseudomorphs is postulated based on SEM observations: (1) complete dissolution of whewellite, possibly caused by oxalotrophic bacteria, and (2) subsequent bacterially...

The Red Dog Zn-Pb deposits are hosted in organic-rich mudstone and shale of the Mississippian Kuna Formation. A complex mineralization history is defined by four sphalerite types or stages: (1) early brown sphalerite, (2) yellow-brown sphalerite, (3) red-brown sphalerite, and (4) late tan sphalerite. Stages 2 and 3 constitute the main ore-forming event and are volumetrically the most important....

Control over the crystallography, morphology and hierarchical assembly of crystals are important goals in advanced materials engineering with important application potential. Most studies hitherto have concentrated on using different templates for the controlled nucleation and growth of ceramic crystals. In this paper, we demonstrate the crystallization of barium sulfate within thermally evapor...

Microbial processes played a major role in mineral precipitation throughout the Earth’s history. Such processes have been widely discussed for the last few decades with regard to carbonate precipitation. Other than microbial precipitation of carbonates, in natural environments is also of great interest the potential role of microbes in the precipitation of marine barite. Regarding carbonates, o...

Barite plaster has been largely used as shielding material in installations housing gamma radiation sources as well as x-ray generating equipment, in order to minimize exposure to individuals. However, some physical characteristics, such as density, plasticity, resistance to compression and radiation attenuation for the different types of barite plaster commercially available in Brazil are not ...

the komshecheh barite-fluorite deposit is the product of epigenetic hydrothermal mineralizationin dolomitized limestone of middle triassic age. the deposit is structurally and lithologically controlled andoccurs predominantly as bedded stratabound replacement sheets, although the veins and solution-collapsebreccias constitute important modes of occurrence. brecciation, dolomitization, silicific...

Barite is an important additive material to increase the weight of excavation mud. It has been used extensively in the excavation mud industry. The barite particle sizes used in excavation mud is very important. There is a direct relationship between the amount on the sift of 200 and 325 mesh. By reducing particle sizes of the 200 and 325 mesh, the specific gravity of the barite power increased...